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[RFC v6 20/62] powerpc: store and restore the pkey state across context switches

From Ram Pai <linuxram@us.ibm.com>
Newsgroups linux.kernel
Subject [RFC v6 20/62] powerpc: store and restore the pkey state across context switches
Date 2017-07-16 06:20 +0200
Message-ID <u3Jce-2ea-33@gated-at.bofh.it> (permalink)
References <u3ISR-1St-3@gated-at.bofh.it>
Organization linux.* mail to news gateway

Show all headers | View raw

Store and restore the AMR, IAMR and UMOR register state of the task
before scheduling out and after scheduling in, respectively.

Signed-off-by: Ram Pai <linuxram@us.ibm.com>
---
 arch/powerpc/include/asm/processor.h |    5 +++++
 arch/powerpc/kernel/process.c        |   18 ++++++++++++++++++
 2 files changed, 23 insertions(+), 0 deletions(-)

diff --git a/arch/powerpc/include/asm/processor.h b/arch/powerpc/include/asm/processor.h
index 1189d04..dcb1cf0 100644
--- a/arch/powerpc/include/asm/processor.h
+++ b/arch/powerpc/include/asm/processor.h
@@ -309,6 +309,11 @@ struct thread_struct {
 	struct thread_vr_state ckvr_state; /* Checkpointed VR state */
 	unsigned long	ckvrsave; /* Checkpointed VRSAVE */
 #endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
+#ifdef CONFIG_PPC64_MEMORY_PROTECTION_KEYS
+	unsigned long	amr;
+	unsigned long	iamr;
+	unsigned long	uamor;
+#endif
 #ifdef CONFIG_KVM_BOOK3S_32_HANDLER
 	void*		kvm_shadow_vcpu; /* KVM internal data */
 #endif /* CONFIG_KVM_BOOK3S_32_HANDLER */
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 2ad725e..9429361 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -1096,6 +1096,11 @@ static inline void save_sprs(struct thread_struct *t)
 		t->tar = mfspr(SPRN_TAR);
 	}
 #endif
+#ifdef CONFIG_PPC64_MEMORY_PROTECTION_KEYS
+	t->amr = mfspr(SPRN_AMR);
+	t->iamr = mfspr(SPRN_IAMR);
+	t->uamor = mfspr(SPRN_UAMOR);
+#endif
 }
 
 static inline void restore_sprs(struct thread_struct *old_thread,
@@ -1131,6 +1136,14 @@ static inline void restore_sprs(struct thread_struct *old_thread,
 			mtspr(SPRN_TAR, new_thread->tar);
 	}
 #endif
+#ifdef CONFIG_PPC64_MEMORY_PROTECTION_KEYS
+	if (old_thread->amr != new_thread->amr)
+		mtspr(SPRN_AMR, new_thread->amr);
+	if (old_thread->iamr != new_thread->iamr)
+		mtspr(SPRN_IAMR, new_thread->iamr);
+	if (old_thread->uamor != new_thread->uamor)
+		mtspr(SPRN_UAMOR, new_thread->uamor);
+#endif
 }
 
 struct task_struct *__switch_to(struct task_struct *prev,
@@ -1689,6 +1702,11 @@ void start_thread(struct pt_regs *regs, unsigned long start, unsigned long sp)
 	current->thread.tm_tfiar = 0;
 	current->thread.load_tm = 0;
 #endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
+#ifdef CONFIG_PPC64_MEMORY_PROTECTION_KEYS
+	current->thread.amr   = 0x0ul;
+	current->thread.iamr  = 0x0ul;
+	current->thread.uamor = 0x0ul;
+#endif /* CONFIG_PPC64_MEMORY_PROTECTION_KEYS */
 }
 EXPORT_SYMBOL(start_thread);
 
-- 
1.7.1

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Thread

[RFC v6 00/62] powerpc: Memory Protection Keys Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:00 +0200
  [RFC v6 11/62] powerpc: initial pkey plumbing Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:00 +0200
  [RFC v6 31/62] powerpc: Handle exceptions caused by pkey violation Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:00 +0200
  [RFC v6 15/62] powerpc: helper functions to initialize AMR, IAMR and UMOR registers Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:00 +0200
  [RFC v6 06/62] powerpc: use helper functions in __hash_page_64K() for 64K PTE Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:00 +0200
  [RFC v6 33/62] powerpc: introduce get_pte_pkey() helper Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:00 +0200
  [RFC v6 26/62] powerpc: Program HPTE key protection bits Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:00 +0200
  [RFC v6 49/62] selftest/vm: fix alloc_random_pkey() to make it really random Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:10 +0200
  [RFC v6 45/62] selftest/vm: generics function to handle shadow key register Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:10 +0200
  [RFC v6 53/62] selftest/vm: powerpc implementation for generic abstraction Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:10 +0200
  [RFC v6 51/62] selftest/vm: pkey register should match shadow pkey Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:10 +0200
  [RFC v6 38/62] powerpc: implementation for arch_pkeys_enabled() Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:10 +0200
  [RFC v6 37/62] x86: implementation for arch_pkeys_enabled() Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:10 +0200
  [RFC v6 46/62] selftest/vm: fix the wrong assert in pkey_disable_set() Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:10 +0200
  [RFC v6 62/62] Documentation/vm: PowerPC specific updates to memory protection keys Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:10 +0200
  [RFC v6 22/62] powerpc: ability to associate pkey to a vma Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:10 +0200
  [RFC v6 27/62] powerpc: helper to validate key-access permissions of a pte Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:10 +0200
  [RFC v6 30/62] powerpc: implementation for arch_vma_access_permitted() Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:10 +0200
  [RFC v6 44/62] selftest/vm: typecast the pkey register Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:10 +0200
  [RFC v6 24/62] powerpc: map vma key-protection bits to pte key bits. Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:10 +0200
  [RFC v6 55/62] selftest/vm: associate key on a mapped page and detect access violation Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:10 +0200
  [RFC v6 58/62] selftest/vm: detect no write key-violation on a freed key Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:10 +0200
  [RFC v6 61/62] Documentation/x86: Move protecton key documentation to arch neutral directory Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:10 +0200
  [RFC v6 52/62] selftest/vm: generic cleanup Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:10 +0200
  [RFC v6 54/62] selftest/vm: fix an assertion in test_pkey_alloc_exhaust() Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:10 +0200
  [RFC v6 60/62] selftest/vm: sub-page allocator Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:10 +0200
  [RFC v6 32/62] powerpc: capture AMR register content on pkey violation Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:10 +0200
  [RFC v6 34/62] powerpc: capture the violated protection key on fault Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:10 +0200
  [RFC v6 50/62] selftest/vm: introduce two arch independent abstraction Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:10 +0200
  [RFC v6 25/62] powerpc: sys_pkey_mprotect() system call Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:10 +0200
  [RFC v6 59/62] selftest/vm: detect write violation on a mapped access-denied-key page Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:10 +0200
  [RFC v6 57/62] selftest/vm: associate key on a mapped page and detect write violation Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:10 +0200
  [RFC v6 36/62] mm: introduce arch_pkeys_enabled() Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:10 +0200
  [RFC v6 40/62] x86: delete arch_show_smap() Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:10 +0200
  [RFC v6 29/62] powerpc: Macro the mask used for checking DSI exception Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:10 +0200
  [RFC v6 47/62] selftest/vm: fixed bugs in pkey_disable_clear() Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:10 +0200
  [RFC v6 28/62] powerpc: check key protection for user page access Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:10 +0200
  [RFC v6 48/62] selftest/vm: clear the bits in shadow reg when a pkey is freed. Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:10 +0200
  [RFC v6 56/62] selftest/vm: detect no key violation on a freed key Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:10 +0200
  [RFC v6 39/62] mm: display pkey in smaps if arch_pkeys_enabled() is true Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:10 +0200
  [RFC v6 42/62] selftest/vm: rename all references to pkru to a generic name Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:10 +0200
  [RFC v6 07/62] powerpc: use helper functions in __hash_page_huge() for 64K PTE Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:20 +0200
  [RFC v6 12/62] mm: introduce an additional vma bit for powerpc pkey Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:20 +0200
  [RFC v6 13/62] powerpc: track allocation status of all pkeys Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:20 +0200
  [RFC v6 09/62] powerpc: use helper functions in __hash_page_4K() for 4K PTE Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:20 +0200
  [RFC v6 01/62] powerpc: Free up four 64K PTE bits in 4K backed HPTE pages Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:20 +0200
  [RFC v6 08/62] powerpc: use helper functions in __hash_page_4K() for 64K PTE Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:20 +0200
  [RFC v6 05/62] powerpc: capture the PTE format changes in the dump pte report Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:20 +0200
  [RFC v6 02/62] powerpc: Free up four 64K PTE bits in 64K backed HPTE pages Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:20 +0200
  [RFC v6 14/62] powerpc: helper function to read,write AMR,IAMR,UAMOR registers Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:20 +0200
  [RFC v6 18/62] powerpc: sys_pkey_alloc() and sys_pkey_free() system calls Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:20 +0200
  [RFC v6 03/62] powerpc: introduce pte_set_hash_slot() helper Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:20 +0200
  [RFC v6 21/62] powerpc: introduce execute-only pkey Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:20 +0200
  [RFC v6 10/62] powerpc: use helper functions in flush_hash_page() Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:20 +0200
  [RFC v6 16/62] powerpc: cleaup AMR,iAMR when a key is allocated or freed Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:20 +0200
  [RFC v6 20/62] powerpc: store and restore the pkey state across context switches Ram Pai <linuxram@us.ibm.com> - 2017-07-16 06:20 +0200

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